[MINI-OS] Fix a bug which prevented map_frames being used more than once. Found by John D. Ramsdell <ramsdell@mitre.org>
[MINI-OS] Fix a bug which prevented map_frames being used more than once.
Found by John D. Ramsdell <ramsdell@mitre.org>

Signed-off-by: Steven Smith <fb240a6ef5c6ffa4867cbb1a385a05c0397eb9c1@cam.ac.uk>

rowhit/xen-minios,rowhit/xen-minios,rowhit/xen-minios